coltan

DR Congo has large deposits of coltan and cobalt, used in electronic equipment and batteries for electric cars, which are currently largely extracted by Chinese mining companies.

The M23 has also seized territory containing mines for coltan ore, which China imports in large volumes.

DR Congo accuses Rwanda of trying to take control of its minerals, which include gold and coltan, used in consumers electronics such as mobile phones and computers.

Last April, it seized Rubaya, the town at the heart of the country's coltan industry.

The province has been unstable for decades with numerous militias operating there making money from its minerals like gold and coltan - used to make batteries for electric vehicles and mobile phones.